Muffler



June 23, 1925.

v. OLDBERG MUFFLER Original Filed lay .23. 1921 I N V EN TOR.

1%RNEY.

Patented June 23, 1925.

UNITED STATES' PATENT OFFICE.

VERGIL OLDBEBG, OF DETROIT, MICHIGAN, ASSIGNOB T OLDBERG MANUFiCTURING COMPANY, OF DETROIT, MICHIGAN, .A. CORPORATION OF MICHIGAN.

' MUFFLER.

Application filed Kay 23, 1921, Serial No. 4 71,688. Renewed March 10, 1824.

To all whom it may concern:

Be it known that I, VIRGIL Omanno, a.

irregular speeds, and while especially adapted for reducing the noises of the exhaustsof internal combustion engines, these mufflers may be employed wherever else gases are drawn inor expelled at intervals or at varying rates. The object of this invention is to provide a mufiler which will cause the least amount of back-pressure and will reduce the sound of the moving gases within the muffler and at the same time eliminate the drumming noises so often noticed in connection with mufilers for exhaust gases.

This invention consists of a plurality of shells, one within the other, and heads to position the shells so that each will be eecentric relative to the next adjacent shell, the inner shell and the heads being perforated to permit the passage of gas, and a diaphragm intermediate the ends of the inner shell to prevent the direct passage of gases the whole length thereof.

It further consists of the details of construction illustrated in the accompanying drawing and particularly pointed out in the claims.

In the accompanying drawing, Fig. 1 is a central longitudinal section of this improved mufller. Fig.2 is an end view thereof. Fig. 3 is a transverse section on the line 33 of Fi .1. Fig.4 is a fragmentary section of as ell.

Similar reference characters refer to like parts throughout the several views. v,

The muflier shown in the drawing consists of the two heads 1 and 2, one provided with an inlet pipe 3 and the other with a discharge pipe 4, an outer shell, 5 which is referably corrugated, thimbles 6 and 7 within the ends thereof, an intermediate shell 8 mounted on the thimbles, a diaphragm 9 0 mounted within the intermediate shell to divide it into twosections, and a two-part inner shell 101l mounted on the thimbles 6 and 7 and on the diaphragm 9.

The'heads 1 and 2 are preferably formed with the circumferential flanges 13 adapted to be welded. to the ends of the outer shell 5, with stiffening ribs 14, and with inner flanges 16 adapted to be welded to the inlet pipe and discharge pipe 4. The thimbles 6 and 'Z' are eachpreferably-formed with circumferential flanges 17 adapted to be welded flange 23' adapted to be welded to the inter-- mediate shell 8 and a cylindrical portion 24 eccentric thereto to which the adjacent ends of the two parts 10 and 11 of the inner shell may be attached. These two parts also have perforations 25 and 26 opposite each other.

Gases entering through the pipe 3 will flow along the inner shell 10 and pass out through the openings 25, then flow around this inner shell, expanding as they reach the greater space between it and the intermediate. shell 8 and then pass through theholes 20 into the space within the outer shell. The gases then move spirally around the intermediate shell to the holes 21 in the intermediate shell and again enter at the opposite side of the diaphragm 9. After again passing half way around the inner shell, the gases enter through the holes 26, and then flow longitudinally to the discharge pipe 4which may be of anydesired b shape and length.

In order that the gases may flow through the openings 20,- 21;, 25 and 26as freely as possible, the metal around these holes should be drawn to thimble form, as indicated in Fig, 4, the-small rings 27 being on those sides of the shells toward which the gases flow through these openings and the entrances of these openings having rounded ,edges.

, The outer shell usually remains at much more even temperature than the intermediate and'inner shells and when. corrugated as shown permits these shells to expand and contract without causing the joints between the shells and thimbles to break. The diaphragm 9 not only causes the gases to take a round-about course, but it reduces the vibration of the inner and intermediate shells which almost entirely eliminates the drum-' ming sound so frequently heard in mufiiers.

The corrugated outer shell still further cuts down this noise, and, because of its great area, serves to cool the gases and thus reduces their volume and the back pressure. It will be noted that in each case, the space between the shells is narrower at the point of entry of the gas and increases in a predetermined degree to the-point of dischar e.

The details of this construction and t e roportions of the parts may all be changed by those skilled in the art without departing from the spirit of my invention as set forth in the following claims.

I claim 1. In a mufiler, the combination of a series of cylindrical shells mounted within each other, heads closing the ends of the outer shell, thimbles within the ends of the outer shell and each having cylindrical extensions intermediate and inner shells mounted on said extensions, the inner shell being concentric with the outer shell and the intermediate shell bein eccentric to the other two, said inner shell. eing in two sections, and a diaphragm mounted in the in-" termediate shell and having a cylindrical projection fitting the adjacent ends of the two sections of the inner shell, said inner and intermediate shells being formed with holes to permit the passage of exhaust gases, the holes in each of the inner shells being along longitudinal lines substantially diametrically opposite each other at opposite sides of the diaphragm.

2. In a mufiler, the combination of a series of cylindrical shells within each other, heads closing the'endsof the outer shell, and sheet metal thimbles within the ends of the outer shell andvformed with inwardly extending cylindrical extensions to receive saidinner shells, the inner extensions being respectively eccentric to and projecting beyond the next outer extensions, said inner shells having holes to permit the passage of gases.

3. In a mufiler, the combination of a plurality of cylindrical outer and inner shells eccentrically mounted within each other, means closing the ends of the outer shell, a diaphragm mounted between the ends of the inner shell, and inlet v and discharge passages connected with the ends of the outer shell, the inner shell being formed with lines of holes to permit the passage of gases, said lines beingsubstantially diametrically opposite each other at opposite sides of the diaphragm and along the plane passing through the axes of the shells,-those portions of the inner shell diametrically opposite the lines of holes being imperforate.

4. In a mufiler, the combination of a series of cylindrical shells eccentrically mounted within each other withtheir axes in substantially the same plane, means closing the ends of all but the inner shell, a diaphragm mounted within and between the ends of all but the outer shell, and inlet and discharge passages connected with the ends of the outer shell, the inner shells being formed with lines of holes to permit the passage of gases, said lines being substantially diametrically opposite each other in each shell at opposite sides of the diaphragm therein, one of the lines of holes of each shell opening into the narrowest and the other into the widest portion of the space surrounding it, those portions of the inner shell diametricall opposite the lines of holes being imper orate.

5. In a muflier, the combination of inner and outer shells, thecentral line of the inner shell being at one side of the central line of the outer shell, and a diaphragm mounted within the inner shell between its ends, said inner shell being formed with lines of holes substantially diametrically opposite each other at opposite sides of the diaphragm, the holes on one'side of the diaphragm opening into the space between the shells where it is narrowest and the other row of holes where such space is widest, those portions of the VIRGIL OLDBERG. 

